CONVERTIBLE NOTE AND WARRANT PURCHASE AGREEMENT

Exhibit 10.19

CONVERTIBLE NOTE AND WARRANT PURCHASE AGREEMENT

This Convertible Note and Warrant Purchase Agreement (the “ Agreement ”) is made as of ____________, by and between Helix BioMedix, Inc., a Delaware corporation (the “ Company ”), and the undersigned (the “ Investor ”).

1. Purchase and Sale; Closing .

1.1 Purchase of Note . Subject to the terms and conditions of this Agreement, the Company agrees to sell to the Investor, and the Investor agrees to purchase from the Company, a Convertible Promissory Note (the “ Note ”) in substantially the form attached hereto as Exhibit A in the principal amount set forth on the signature page hereto. The Note will be convertible into equity securities of the Company upon the terms and conditions contained in the form of Note attached hereto as Exhibit A . Shares of equity securities of the Company issued upon conversion of the Note are referred to herein as the “ Note Shares .”

1.2 Purchase of Warrant . Subject to the terms and conditions of this Agreement, the Company agrees to sell to the Investor, and the Investor agrees to purchase from the Company, a Warrant (the “ Warrant ”) in substantially the form attached hereto as Exhibit B . The Warrant will be exercisable for shares of the Company’s Common Stock upon the terms and conditions contained in the form of Warrant attached hereto as Exhibit B . Shares of the Company’s Common Stock issued upon exercise of the Warrant are referred to herein as the “ Warrant Shares .” The Note, the Warrant, the Note Shares and the Warrant Shares are sometimes collectively referred to herein as the “ Securities .”

1.3 Closing . The closing of the sale and issuance of the Note and Warrant shall be held at such time and place upon which the Company and the Investor shall agree (hereinafter referred to as the “ Closing ”). The date of the Closing is referred to herein as the “ Closing Date .”

2. Representations of the Company .

The Company represents and warrants to the Investor as follows:

2.1 Organization and Standing . The Company is a corporation duly organized and existing under, and by virtue of, the laws of the State of Delaware and is in good standing under such laws.

2.2 Corporate Power . The Company will have at the Closing all requisite legal and corporate power and authority to execute and deliver this Agreement, to sell and issue the Securities and to carry out and perform its obligations under the terms of this Agreement.

2.3 Authorization . All corporate action on the part of the Company necessary for the authorization, execution, delivery and performance of this Agreement by the Company, the authorization, sale, issuance and delivery of the Note and the Warrant and the performance of all of the Company’s obligations hereunder and thereunder has been taken or will be taken prior to the Closing. This Agreement, the Note and Warrant, when executed and delivered by the Company, shall constitute valid and binding obligations of the Company, enforceable in accordance with their respective terms, subject to laws of general application relating to bankruptcy, insolvency and the relief of debtors and rules of law governing specific performance, injunctive relief or other equitable remedies. The Note Shares, when issued in compliance with the provisions of the Note, will be validly issued, fully paid and nonassessable, and will be free of any liens or encumbrances, assuming that the Investor takes the Note Shares with no notice thereof, other than any liens or encumbrances created by or imposed upon the Investor; provided, however, that the Note Shares will be

subject to restrictions on transfer under state and/or federal securities laws. The Warrant Shares, when issued in compliance with the provisions of the Warrant, will be validly issued, fully paid and nonassessable, and will be free of any liens or encumbrances, assuming that the Investor takes the Warrant Shares with no notice thereof, other than any liens or encumbrances created by or imposed upon the Investor; provided, however, that the Warrant Shares will be subject to restrictions on transfer under state and/or federal securities laws.

2.4 No Finder’s Fees . No person is entitled, directly or indirectly, to compensation from the Company by reason of any contract or understanding or contact with the Company as a finder or broker in connection with this sale and purchase of the Note and Warrant contemplated by this Agreement. The Company agrees to indemnify and hold the Investor harmless against and respect of any claim of brokerage or other commissions or similar fees relative to this Agreement or the transactions contemplated hereby which arises as a result of a contract or understanding made by the Company with any such broker or finder in connection with this sale and purchase of the Note and Warrant contemplated by this Agreement.

3. Representations of Investors . The Investor hereby represents and warrants to the Company with respect to its purchase of the Note and Warrant as follows:

3.1 Investment . The Investor understands that the investment in the Securities is a speculative investment and represents that it is aware of the business affairs and financial condition of the Company and has acquired sufficient information about the Company to reach an informed and knowledgeable decision to acquire the Note and Warrant, and that it is purchasing the Note and Warrant for investment for its own account only and not with a view to, or for resale in connection with, any “distribution” within the meaning of the Securities Act of 1933, as amended (the “ Securities Act ”) or applicable state securities laws. The Investor further represents that it understands that the Securities have not been registered under the Securities Act or applicable state securities laws by reason of specific exemptions therefrom, which exemptions depend upon, among other things, the bona fide nature of the Investor’s investment intent as expressed herein. The Investor acknowledges and understands that the Securities must be held indefinitely unless subsequently registered under the Securities Act and qualified under applicable state securities laws or unless exemptions from such registration and qualification requirements are available and that the Company is under no obligation to register or qualify the Securities.

3.2 Accredited Investor . The Investor is an accredited investor as defined in Rule 501(a) of Regulation D promulgated under the Securities Act.

3.3 Access to Data . The Investor acknowledges that it has received and reviewed this Agreement and exhibits hereto. The Investor has had an opportunity to discuss the Company’s business, management and financial affairs with its officers and directors. The Investor understands that such discussions as well as any written information issued by the Company were intended to describe the aspects of the Company’s business and prospects which it believes to be material but were not necessarily a thorough or exhaustive description.

3.4 No Finder’s Fees . No person is entitled, directly or indirectly, to compensation from the Investor by reason of any contract or understanding or contact with the Investor as a finder or broker in connection with the sale and purchase of the Note and Warrant contemplated by this Agreement. Investor agrees to indemnify and hold the Company harmless against and in respect of any claim for brokerage or other commissions or similar fees relative to this Agreement or the transactions contemplated hereby which arises as a result of a contract or understanding made by the Investor with any such broker or finder in connection with the sale and purchase of the Note and Warrant contemplated by this Agreement.

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3.5 Legends . The Investor understands that the Securities, and any securities issued in respect thereof or exchange therefor, may bear one or all of the following legends:

(a) “THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 AND HAVE BEEN ACQUIRED FOR INVESTMENT AND NOT WITH A VIEW TO, OR IN CONNECTION WITH, THE SALE OR DISTRIBUTION THEREOF. NO SUCH SALE OR DISTRIBUTION MAY BE EFFECTED WITHOUT AN EFFECTIVE REGISTRATION STATEMENT RELATED THERETO OR AN OPINION OF COUNSEL IN A FORM SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED UNDER THE SECURITIES ACT OF 1933.”

(b) Any legend required by the blue sky laws of any state to the extent such laws are applicable to the Securities represented by the certificate so legended.

4. Condition to Investor’s Obligations at Closing . The Investor’s obligation to purchase the Note and Warrant at the Closing is subject to the fulfillment on or prior to the Closing Date of the following condition:

4.1 Representations and Warranties Correct . The representations and warranties made by the Company in Section 2 hereof shall be true and correct when made and shall be true and correct on the Closing Date.

5. Conditions to the Company’s Obligations at Closing . The Company’s obligation to sell and issue the Note and Warrant at the Closing is subject to the fulfillment of the following conditions:

5.1 Representations and Warranties Correct . The representations and warranties made by the Investor in Section 3 hereof shall be true and correct when made and shall be true and correct on the Closing Date.

5.2 Qualifications . All authorizations, approvals or permits, if any, of any governmental authority or regulatory body of the United States or of any state that are required in connection with the lawful issuance and sale of the Securities pursuant to this Agreement shall be obtained and effective as of the Closing.

5.3 Board Approval . The Company’s Board of Directors shall have authorized the sale and issuance of the Securities.

6. Miscellaneous .

6.1 Governing Law; Venue . This Agreement, the Note and the Warrant shall in all respects be governed by and construed and enforced in accordance with the laws of the State of Washington, as such laws apply to contracts entered into and wholly to be performed within such state. The parties expressly stipulate that any litigation under this Agreement shall be brought in the state courts of King County, Washington or in the United States District Court for the Western District of Washington. The parties agree to submit to the exclusive jurisdiction and venue of those courts.

6.2 Successors and Assigns . Except as otherwise provided herein, the provisions hereof shall inure to the benefit of, and be binding upon, the successors, assigns, heirs, executors and administrators of the parties hereto, provided, however, that the rights of the Investor to purchase the Note and Warrant shall not be assignable without the consent of the Company and provided further that the Company may not assign its rights hereunder.

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6.3 Entire Agreement; Amendment . This Agreement, the Note, the Warrant and the other documents delivered pursuant hereto constitute the full and entire understanding and agreement between the parties with regard to the subject matter hereof and thereof, and no party shall be liable or bound to any other party in any manner by any warranties, representations or covenants except as specifically set forth herein or therein. Except as expressly provided herein, neither this Agreement nor any term hereof may be amended, waived, discharged or terminated other than by a written instrument signed by the party against whom enforcement of any such amendment, waiver, discharge or termination is sought.

6.4 Notices, etc . All notices and other communications under this Agreement shall be in writing and shall be delivered in person, via facsimile machine, sent by documented overnight delivery service, or mailed by registered or certified mail, return receipt requested, postage prepaid, addressed (a) if to the Investor, at the address of the Investor set forth on the signature page of this Agreement, or (b) if to the Company, to the attention of its President at its principal offices at 22118 20th Avenue SE, Suite 204, Bothell, WA 98021. Unless otherwise specified in this Agreement, all such notices and other written communications shall be effective (and considered delivered and received for the purposes of this Agreement) (i) if delivered, upon delivery, (ii) if by facsimile machine during normal business hours upon transmission with confirmation of receipt by the receiving party’s facsimile terminal and if not sent during normal business hours, then on the next day, (iii) if sent by documented overnight delivery service, on the date following the date on which such notice is delivered to such overnight delivery service for mailing, or (iv) if mailed via first-class regular mail, three (3) day after depositing in the U.S. Mail.

6.5 Expenses; Attorneys Fees . Each of the Company and the Investor shall each bear its own expenses incurred on its behalf with respect to this Agreement and the transactions contemplated hereby. Notwithstanding the foregoing, if any action at law or in equity (including arbitration) is necessary to enforce or interpret the terms of this Agreement, the Note or the Warrant, the prevailing party shall be entitled to reasonable attorney’s fees, costs and necessary disbursements in addition to any other relief to which such party may be entitled.

6.6 Counterparts . This Agreement may be executed in any number of counterparts, each of which shall be enforceable against the party or parties actually executing such counterparts, and all of which together shall constitute one instrument.

6.7 Titles and Subtitles . The titles and subtitles used in this Agreement are used for convenience only and are not considered in construing or interpreting this Agreement.

[Remainder of Page Intentionally Left Blank]

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The foregoing Agreement is hereby executed as of the date first above written.

[Signature Page to Convertible Note and Warrant Purchase Agreement]

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EXHIBIT A

THIS NOTE AND THE SECURITIES ISSUABLE UPON CONVERSION HEREOF HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “ACT”), OR ANY STATE SECURITIES LAWS. THEY MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED, HYPOTHECATED OR OTHERWISE TRANSFERRED IN THE ABSENCE OF A REGISTRATION STATEMENT IN EFFECT WITH RESPECT TO THE SECURITIES UNDER SUCH ACT AND APPLICABLE STATE SECURITIES LAWS OR UNLESS (i) SOLD PURSUANT TO AN EXEMPTION FROM REGISTRATION UNDER SUCH ACT AND APPLICABLE STATE SECURITIES LAWS AND (ii) AT THE OPTION OF THE COMPANY, AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED HAS BEEN DELIVERED TO THE COMPANY.

HELIX BIOMEDIX, INC.

CONVERTIBLE PROMISSORY NOTE

                         , 2008

FOR VALUE RECEIVED , Helix BioMedix, Inc., a Delaware corporation (“ Company ”), promises to pay to                          (“ Holder ”), or his registered assigns, the principal sum of                          Dollars ($                          ), or such lesser amount as shall then equal the outstanding principal amount hereof, together with interest from the date of this Note on the unpaid principal balance at a rate equal to eight percent (8%) per annum, computed on the basis of the actual number of days elapsed. All unpaid principal, together with any then unpaid and accrued interest and other amounts payable hereunder, shall be due and payable on the earlier of (i) July 1, 2011 (the “ Maturity Date ”) or (ii) when such amounts are declared due and payable by the Holder or made automatically due and payable, in each case upon or after the occurrence of an Event of Default (as defined below). This Note is issued pursuant to the Convertible Note Purchase Agreement of even date herewith (as amended, modified or supplemented, the “ Purchase Agreement ”) between Company and the Investor (as defined in the Purchase Agreement) and is one of several convertible promissory notes issued on or about the date hereof (the “ Notes ”).

The following is a statement of the rights of Holder and the conditions to which this Note is subject, and to which the Holder hereof, by the acceptance of this Note, agrees:

1. Definitions . As used in this Note, the following capitalized terms have the following meanings:

(a) “ Company ” includes the corporation initially executing this Note and any Person which shall succeed to or assume the obligations of Company under this Note.

(b) “ Holder ” shall mean the Person specified in the introductory paragraph of this Note or any Person who shall at the time be the registered holder of this Note.

(c) “ Person ” shall mean and include an individual, a partnership, a corporation (including a business trust), a joint stock company, a limited liability company, an unincorporated association, a joint venture or other entity or a governmental authority.

2. Interest . Accrued interest on this Note shall be payable at such time as the outstanding principal amount hereof shall be paid in full.

3. Events of Default . The occurrence of any of the following shall constitute an “ Event of Default ” under this Note:

(a) Failure to Pay . Company shall fail in any material respect to pay any principal payment, any interest or other payment required under the terms of this Note on the date due and such payment shall not have been made within fifteen (15) days of Company’s receipt of Holder’s written notice to Company of such failure to pay; or

(b) Breaches of Covenants . Company shall fail in any material respect to observe or perform any covenant, obligation, condition or agreement contained in this Note (other than those covenants specified in Section 3(a) hereof) and such failure shall continue for thirty (30) days after Company’s receipt of Holder’s written notice to Company thereof; or

(c) Representations and Warranties . Any representation or warranty made by Company to Holder in this Note shall be untrue in any material respect when made; or

(d) Voluntary Bankruptcy or Insolvency Proceedings . Company shall (i) apply for or consent to the appointment of a receiver, trustee, liquidator or custodian of itself or of all or a substantial part of its property, (ii) admit in writing its inability to pay its debts generally as they mature, (iii) make a general assignment for the benefit of its or any of its creditors, (iv) be dissolved or liquidated in full or in part, (v) commence a voluntary case or other proceeding seeking liquidation, reorganization or other relief with respect to itself or its debts under any bankruptcy, insolvency or other similar law now or hereafter in effect or consent to any such relief or to the appointment of or taking possession of its property by any official in an involuntary case or other proceeding commenced against it, or (vi) take any action for the purpose of effecting any of the foregoing; or

(e) Involuntary Bankruptcy or Insolvency Proceedings . Proceedings for the appointment of a receiver, trustee, liquidator or custodian of Company or of all or a substantial part of the property thereof, or an involuntary case or other proceedings seeking liquidation, reorganization or other relief with respect to Company or the debts thereof under any bankruptcy, insolvency or other similar law now or hereafter in effect shall be commenced and an order for relief entered or such proceeding shall not be dismissed or discharged within sixty (60) days of commencement.

4. Rights of Holder upon Default . Upon the occurrence or existence of any Event of Default (other than an Event of Default referred to in Sections 3(d) and 3(e) hereof) and at any time thereafter during the continuance of such Event of Default, Holder may, by written notice to Company, declare all outstanding obligations payable by Company hereunder to be immediately due and payable without presentment, demand, protest or any other notice of any kind, all of which are hereby expressly waived, anything contained herein to the contrary notwithstanding. Upon the occurrence or existence of any Event of Default described in Sections 3(d) and 3(e) hereof, immediately and without notice, all outstanding obligations payable by Company hereunder shall automatically become immediately due and payable, without presentment, demand, protest or any other notice of any kind, all of which are hereby expressly waived, anything contained herein to the contrary notwithstanding. In addition to the foregoing remedies, upon the occurrence or existence of any Event of Default, Holder may exercise any other right, power or remedy permitted to it by law, either by suit in equity or by action at law, or both.

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5. Conversion .

(a) Automatic Conversion upon Equity Financing . Upon the closing (or first in a series of closings) of the next equity financing in which Company sells shares of its equity securities (the “ Equity Securities ”) for an aggregate consideration of at least $7,500,000 (including the aggregate principal and accrued interest due on this Note) (the “ Equity Financing ”), the principal and accrued interest due on this Note shall automatically be converted into shares of the Equity Securities as set forth in Section 5(e) below. The conversion shall be deemed to have occurred as of the date of such closing or the date of the first closing in a series of closings. As a condition precedent (which may be waived by the Company) to conversion of this Note as provided for in this Section 5(a), the Holder will be required to execute the definitive Stock Purchase Agreement and such other agreements prepared in connection with the Equity Financing. The number of shares of Equity Securities into which this Note shall be automatically converted shall be determined by dividing the principal and accrued interest due on this Note as of the date of conversion by an amount equal to the lesser of (i) the per share price of the Equity Securities issued and sold in the Equity Financing and (ii) $1.00.

(b) Automatic Conversion upon Corporate Transaction . Upon the closing of a sale of substantially all of the Company’s assets or a merger or consolidation of the Company in which the Company’s stockholders will hold, in the aggregate, less than 50% of the voting power of the combined entity, the principal and accrued interest due on this Note shall automatically be converted into shares of the Company’s Common Stock as set forth in Section 5(e) below. The conversion shall be deemed to have occurred as of the date of such closing. The number of shares of Common Stock into which this Note shall be automatically converted shall be determined by dividing the principal and accrued interest due on this Note as of the date of conversion by an amount equal to the lesser of (i) the per share price attributed to the Company’s Common Stock in connection with such transaction and (ii) $1.00.

(c) Automatic Conversion upon Debt Financing . Upon consummation by the Company of the sale and issuance of Notes in an aggregate principal amount of $10.5 million, the principal and accrued interest due on this Note shall automatically be converted into equity securities of the Company on terms and conditions mutually agreed upon by the Company and the holder(s) of a majority-in-interest of then-outstanding Notes and as set forth in Section 5(e) below. The conversion shall be deemed to have occurred as of the date of such closing.

(d) Voluntary Conversion at Maturity Date . At and as of the Maturity Date, to the extent this Note is still outstanding and has not otherwise been converted or repaid in full, the Holder will have the option, in its sole discretion, to convert this Note into shares of the Company’s Common Stock. The number of shares of Common Stock into which this Note may be voluntarily converted shall be determined by dividing the principal and accrued interest due on this Note as of the date of conversion by $1.00.

(e) Issuance of Securities on Conversion . As soon as practicable after conversion of this Note, Company, at its expense, will cause to be issued in the name of and delivered to the Holder a certificate or certificates representing the number of fully paid and nonassessable shares of the Equity Securities or Common Stock (as applicable) to which Holder shall be entitled upon such conversion. No fractional shares will be issued upon conversion of this Note.

(f) Termination of Rights . All rights with respect to this Note shall terminate upon conversion hereof in accordance with this Section 5, whether or not this Note has been surrendered. Notwithstanding the foregoing, the Holder agrees to surrender this Note to Company for cancellation as soon as is practicable following conversion of this Note.

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6. Successors and Assigns . Subject to the restrictions on transfer described in Section 8 below, the rights and obligations of Company and Holder shall be binding upon and benefit the successors, assigns, heirs, administrators and transferees of the parties.

7. Waiver and Amendment . Any provision of this Note may be amended, waived or modified upon the written consent of Company and Holder.

8. Transfer of this Note or Securities Issuable Upon Conversion Hereof . With respect to any contemplated offer, sale or other disposition of this Note or securities into which such Note may be converted, the Holder will first give written notice to Company prior thereto, describing briefly the manner thereof, together with a written opinion of the Holder’s counsel to the effect that such offer, sale or other disposition may be effected without registration or qualification under any federal or state law then in effect. Promptly upon receiving such written notice and reasonably satisfactory opinion, if so requested, Company, as promptly as practicable, shall notify the Holder that the Holder may sell or otherwise dispose of this Note or such securities, all in accordance with the terms of the notice delivered to Company. If a d